Improved error handling in commands

- Changed all "status != 200" to raise a custom exception
- Raise appropriate exceptions in 'grid'
- Removed command-specific error handling in 'extctl' commands

Fixes #146

CHANGELOG.md

@@ -15,6 +15,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - All currently-available pools can now be accessed by the `hamstudy` command.
 - The `hamstudy` command now uses the syntax `?hamstudy <country> <pool>`.
 - Replaced `hamstudyanswer` command with answering by reaction.
+- Removed all generic error handling from commands.
 ### Fixed
 - Fixed ditto marks (") appearing in the ae7q call command.
 - Fixed issue where incorrect table was parsed in ae7q call command.

common.py

@@ -16,6 +16,8 @@ from datetime import datetime
 from pathlib import Path
 from types import SimpleNamespace
 
+import aiohttp
+
 import discord
 import discord.ext.commands as commands
 
@@ -95,6 +97,18 @@ class ImagesGroup(collections.abc.Mapping):
         return str(self._images)
 
 
+# --- Exceptions ---
+
+class BotHTTPError(Exception):
+    """Raised whan a requests fails (status != 200) in a command."""
+    def __init__(self, response: aiohttp.ClientResponse):
+        msg = f"Request failed: {response.status} {response.reason}"
+        super().__init__(msg)
+        self.response = response
+        self.status = response.status
+        self.reason = response.reason
+
+
 # --- Converters ---
 
 class GlobalChannelConverter(commands.IDConverter):

exts/ae7q.py

@@ -44,11 +44,7 @@ class AE7QCog(commands.Cog):
 
             async with self.session.get(base_url + callsign) as resp:
                 if resp.status != 200:
-                    embed.title = "Error in AE7Q call command"
+                    raise cmn.BotHTTPError(resp)
-                    embed.description = 'Could not load AE7Q'
-                    embed.colour = cmn.colours.bad
-                    await ctx.send(embed=embed)
-                    return
                 page = await resp.text()
 
             soup = BeautifulSoup(page, features="html.parser")
@@ -114,11 +110,7 @@ class AE7QCog(commands.Cog):
 
             async with self.session.get(base_url + callsign) as resp:
                 if resp.status != 200:
-                    embed.title = "Error in AE7Q trustee command"
+                    raise cmn.BotHTTPError(resp)
-                    embed.description = 'Could not load AE7Q'
-                    embed.colour = cmn.colours.bad
-                    await ctx.send(embed=embed)
-                    return
                 page = await resp.text()
 
             soup = BeautifulSoup(page, features="html.parser")
@@ -186,11 +178,7 @@ class AE7QCog(commands.Cog):
 
             async with self.session.get(base_url + callsign) as resp:
                 if resp.status != 200:
-                    embed.title = "Error in AE7Q applications command"
+                    raise cmn.BotHTTPError(resp)
-                    embed.description = 'Could not load AE7Q'
-                    embed.colour = cmn.colours.bad
-                    await ctx.send(embed=embed)
-                    return
                 page = await resp.text()
 
             soup = BeautifulSoup(page, features="html.parser")
@@ -245,7 +233,8 @@ class AE7QCog(commands.Cog):
 
             await ctx.send(embed=embed)
         """
-        pass
+        raise NotImplementedError("Application history lookup not yet supported. "
+                                  "Check back in a later version of the bot.")
 
     @_ae7q_lookup.command(name="frn", aliases=["f"], category=cmn.cat.lookup)
     async def _ae7q_frn(self, ctx: commands.Context, frn: str):
@@ -261,11 +250,7 @@ class AE7QCog(commands.Cog):
 
             async with self.session.get(base_url + frn) as resp:
                 if resp.status != 200:
-                    embed.title = "Error in AE7Q frn command"
+                    raise cmn.BotHTTPError(resp)
-                    embed.description = 'Could not load AE7Q'
-                    embed.colour = cmn.colours.bad
-                    await ctx.send(embed=embed)
-                    return
                 page = await resp.text()
 
             soup = BeautifulSoup(page, features="html.parser")
@@ -328,11 +313,7 @@ class AE7QCog(commands.Cog):
 
             async with self.session.get(base_url + licensee_id) as resp:
                 if resp.status != 200:
-                    embed.title = "Error in AE7Q licensee command"
+                    raise cmn.BotHTTPError(resp)
-                    embed.description = 'Could not load AE7Q'
-                    embed.colour = cmn.colours.bad
-                    await ctx.send(embed=embed)
-                    return
                 page = await resp.text()
 
             soup = BeautifulSoup(page, features="html.parser")

exts/grid.py

@@ -24,7 +24,6 @@ class GridCog(commands.Cog):
 with negative being latitude South and longitude West.'''
         with ctx.typing():
             grid = "**"
-            try:
             latf = float(lat) + 90
             lonf = float(lon) + 180
             if 0 <= latf <= 180 and 0 <= lonf <= 360:
@@ -40,11 +39,12 @@ with negative being latitude South and longitude West.'''
                 embed.description = grid
                 embed.colour = cmn.colours.good
             else:
-                    raise ValueError('Out of range.')
-            except ValueError as err:
                 embed = cmn.embed_factory(ctx)
                 embed.title = f'Error generating grid square for {lat}, {lon}.'
-                embed.description = str(err)
+                embed.description = ("Coordinates out of range.\n"
+                                     "The valid ranges are:\n"
+                                     "- Latitude: `-90` to `+90`\n"
+                                     "- Longitude: `-180` to `+180`")
                 embed.colour = cmn.colours.bad
         await ctx.send(embed=embed)
 

exts/image.py

@@ -90,10 +90,7 @@ class ImageCog(commands.Cog):
             embed.colour = cmn.colours.good
             async with self.session.get(self.gl_url) as resp:
                 if resp.status != 200:
-                    embed.description = 'Could not download file...'
+                    raise cmn.BotHTTPError(resp)
-                    embed.colour = cmn.colours.bad
-                    await ctx.send(embed=embed)
-                    return
                 data = io.BytesIO(await resp.read())
             embed.set_image(url=f'attachment://greyline.jpg')
             await ctx.send(embed=embed, file=discord.File(data, 'greyline.jpg'))

exts/morse.py

@@ -68,7 +68,7 @@ class MorseCog(commands.Cog):
                     weight += len(cw_char) * 2 + 2
                 except KeyError:
                     embed.title = 'Error in calculation of CW weight'
-                    embed.description = f'Unknown character {char} in callsign'
+                    embed.description = f'Unknown character `{char}` in message'
                     embed.colour = cmn.colours.bad
                     await ctx.send(embed=embed)
                     return

exts/study.py

@@ -110,11 +110,7 @@ class StudyCog(commands.Cog):
 
             async with self.session.get(f'https://hamstudy.org/pools/{pool}') as resp:
                 if resp.status != 200:
-                    embed.title = 'Error in HamStudy command'
+                    raise cmn.BotHTTPError(resp)
-                    embed.description = 'Could not load questions'
-                    embed.colour = cmn.colours.bad
-                    await ctx.send(embed=embed)
-                    return
                 pool = json.loads(await resp.read())['pool']
 
             # Select a question
@@ -172,7 +168,7 @@ class StudyCog(commands.Cog):
     async def hamstudy_get_pools(self):
         async with self.session.get('https://hamstudy.org/pools/') as resp:
             if resp.status != 200:
-                raise ConnectionError
+                raise cmn.BotHTTPError(resp)
             else:
                 pools_dict = json.loads(await resp.read())
 

exts/weather.py

@@ -34,10 +34,7 @@ class WeatherCog(commands.Cog):
             embed.colour = cmn.colours.good
             async with self.session.get('http://www.hamqsl.com/solarsun.php') as resp:
                 if resp.status != 200:
-                    embed.description = 'Could not download file...'
+                    raise cmn.BotHTTPError(resp)
-                    embed.colour = cmn.colours.bad
-                    await ctx.send(embed=embed)
-                    return
                 data = io.BytesIO(await resp.read())
             embed.set_image(url=f'attachment://condx.png')
             await ctx.send(embed=embed, file=discord.File(data, 'condx.png'))
@@ -84,10 +81,7 @@ See help for weather command for possible location types. Add a `-c` or `-f` to
             loc = loc.replace(' ', '+')
             async with self.session.get(f'http://wttr.in/{loc}_{units}pnFQ.png') as resp:
                 if resp.status != 200:
-                    embed.description = 'Could not download file...'
+                    raise cmn.BotHTTPError(resp)
-                    embed.colour = cmn.colours.bad
-                    await ctx.send(embed=embed)
-                    return
                 data = io.BytesIO(await resp.read())
             embed.set_image(url=f'attachment://wttr_forecast.png')
             await ctx.send(embed=embed, file=discord.File(data, 'wttr_forecast.png'))
@@ -118,10 +112,7 @@ See help for weather command for possible location types. Add a `-c` or `-f` to
             loc = loc.replace(' ', '+')
             async with self.session.get(f'http://wttr.in/{loc}_0{units}pnFQ.png') as resp:
                 if resp.status != 200:
-                    embed.description = 'Could not download file...'
+                    raise cmn.BotHTTPError(resp)
-                    embed.colour = cmn.colours.bad
-                    await ctx.send(embed=embed)
-                    return
                 data = io.BytesIO(await resp.read())
             embed.set_image(url=f'attachment://wttr_now.png')
             await ctx.send(embed=embed, file=discord.File(data, 'wttr_now.png'))

main.py

@@ -103,12 +103,8 @@ async def _extctl_list(ctx: commands.Context):
 
 @_extctl.command(name="load", aliases=["ld"])
 async def _extctl_load(ctx: commands.Context, extension: str):
-    try:
     bot.load_extension(ext_dir + "." + extension)
     await cmn.add_react(ctx.message, cmn.emojis.check_mark)
-    except commands.ExtensionError as ex:
-        embed = cmn.error_embed_factory(ctx, ex, bot.qrm.debug_mode)
-        await ctx.send(embed=embed)
 
 
 @_extctl.command(name="reload", aliases=["rl", "r", "relaod"])
@@ -117,22 +113,14 @@ async def _extctl_reload(ctx: commands.Context, extension: str):
         pika = bot.get_emoji(opt.pika)
         if pika:
             await cmn.add_react(ctx.message, pika)
-    try:
     bot.reload_extension(ext_dir + "." + extension)
     await cmn.add_react(ctx.message, cmn.emojis.check_mark)
-    except commands.ExtensionError as ex:
-        embed = cmn.error_embed_factory(ctx, ex, bot.qrm.debug_mode)
-        await ctx.send(embed=embed)
 
 
 @_extctl.command(name="unload", aliases=["ul"])
 async def _extctl_unload(ctx: commands.Context, extension: str):
-    try:
     bot.unload_extension(ext_dir + "." + extension)
     await cmn.add_react(ctx.message, cmn.emojis.check_mark)
-    except commands.ExtensionError as ex:
-        embed = cmn.error_embed_factory(ctx, ex, bot.qrm.debug_mode)
-        await ctx.send(embed=embed)
 
 
 # --- Events ---